mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
201 lines
5.0 KiB
201 lines
5.0 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* System Control and Management Interface (SCMI) Message Mailbox Transport |
|
* driver. |
|
* |
|
* Copyright (C) 2019 ARM Ltd. |
|
*/ |
|
|
|
#include <linux/err.h> |
|
#include <linux/device.h> |
|
#include <linux/mailbox_client.h> |
|
#include <linux/of.h> |
|
#include <linux/of_address.h> |
|
#include <linux/slab.h> |
|
|
|
#include "common.h" |
|
|
|
/** |
|
* struct scmi_mailbox - Structure representing a SCMI mailbox transport |
|
* |
|
* @cl: Mailbox Client |
|
* @chan: Transmit/Receive mailbox channel |
|
* @cinfo: SCMI channel info |
|
* @shmem: Transmit/Receive shared memory area |
|
*/ |
|
struct scmi_mailbox { |
|
struct mbox_client cl; |
|
struct mbox_chan *chan; |
|
struct scmi_chan_info *cinfo; |
|
struct scmi_shared_mem __iomem *shmem; |
|
}; |
|
|
|
#define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl) |
|
|
|
static void tx_prepare(struct mbox_client *cl, void *m) |
|
{ |
|
struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl); |
|
|
|
shmem_tx_prepare(smbox->shmem, m); |
|
} |
|
|
|
static void rx_callback(struct mbox_client *cl, void *m) |
|
{ |
|
struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl); |
|
|
|
scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem)); |
|
} |
|
|
|
static bool mailbox_chan_available(struct device *dev, int idx) |
|
{ |
|
return !of_parse_phandle_with_args(dev->of_node, "mboxes", |
|
"#mbox-cells", idx, NULL); |
|
} |
|
|
|
static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, |
|
bool tx) |
|
{ |
|
const char *desc = tx ? "Tx" : "Rx"; |
|
struct device *cdev = cinfo->dev; |
|
struct scmi_mailbox *smbox; |
|
struct device_node *shmem; |
|
int ret, idx = tx ? 0 : 1; |
|
struct mbox_client *cl; |
|
resource_size_t size; |
|
struct resource res; |
|
|
|
smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL); |
|
if (!smbox) |
|
return -ENOMEM; |
|
|
|
shmem = of_parse_phandle(cdev->of_node, "shmem", idx); |
|
ret = of_address_to_resource(shmem, 0, &res); |
|
of_node_put(shmem); |
|
if (ret) { |
|
dev_err(cdev, "failed to get SCMI %s shared memory\n", desc); |
|
return ret; |
|
} |
|
|
|
size = resource_size(&res); |
|
smbox->shmem = devm_ioremap(dev, res.start, size); |
|
if (!smbox->shmem) { |
|
dev_err(dev, "failed to ioremap SCMI %s shared memory\n", desc); |
|
return -EADDRNOTAVAIL; |
|
} |
|
|
|
cl = &smbox->cl; |
|
cl->dev = cdev; |
|
cl->tx_prepare = tx ? tx_prepare : NULL; |
|
cl->rx_callback = rx_callback; |
|
cl->tx_block = false; |
|
cl->knows_txdone = tx; |
|
|
|
smbox->chan = mbox_request_channel(cl, tx ? 0 : 1); |
|
if (IS_ERR(smbox->chan)) { |
|
ret = PTR_ERR(smbox->chan); |
|
if (ret != -EPROBE_DEFER) |
|
dev_err(cdev, "failed to request SCMI %s mailbox\n", |
|
tx ? "Tx" : "Rx"); |
|
return ret; |
|
} |
|
|
|
cinfo->transport_info = smbox; |
|
smbox->cinfo = cinfo; |
|
|
|
return 0; |
|
} |
|
|
|
static int mailbox_chan_free(int id, void *p, void *data) |
|
{ |
|
struct scmi_chan_info *cinfo = p; |
|
struct scmi_mailbox *smbox = cinfo->transport_info; |
|
|
|
if (smbox && !IS_ERR(smbox->chan)) { |
|
mbox_free_channel(smbox->chan); |
|
cinfo->transport_info = NULL; |
|
smbox->chan = NULL; |
|
smbox->cinfo = NULL; |
|
} |
|
|
|
scmi_free_channel(cinfo, data, id); |
|
|
|
return 0; |
|
} |
|
|
|
static int mailbox_send_message(struct scmi_chan_info *cinfo, |
|
struct scmi_xfer *xfer) |
|
{ |
|
struct scmi_mailbox *smbox = cinfo->transport_info; |
|
int ret; |
|
|
|
ret = mbox_send_message(smbox->chan, xfer); |
|
|
|
/* mbox_send_message returns non-negative value on success, so reset */ |
|
if (ret > 0) |
|
ret = 0; |
|
|
|
return ret; |
|
} |
|
|
|
static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret) |
|
{ |
|
struct scmi_mailbox *smbox = cinfo->transport_info; |
|
|
|
/* |
|
* NOTE: we might prefer not to need the mailbox ticker to manage the |
|
* transfer queueing since the protocol layer queues things by itself. |
|
* Unfortunately, we have to kick the mailbox framework after we have |
|
* received our message. |
|
*/ |
|
mbox_client_txdone(smbox->chan, ret); |
|
} |
|
|
|
static void mailbox_fetch_response(struct scmi_chan_info *cinfo, |
|
struct scmi_xfer *xfer) |
|
{ |
|
struct scmi_mailbox *smbox = cinfo->transport_info; |
|
|
|
shmem_fetch_response(smbox->shmem, xfer); |
|
} |
|
|
|
static void mailbox_fetch_notification(struct scmi_chan_info *cinfo, |
|
size_t max_len, struct scmi_xfer *xfer) |
|
{ |
|
struct scmi_mailbox *smbox = cinfo->transport_info; |
|
|
|
shmem_fetch_notification(smbox->shmem, max_len, xfer); |
|
} |
|
|
|
static void mailbox_clear_channel(struct scmi_chan_info *cinfo) |
|
{ |
|
struct scmi_mailbox *smbox = cinfo->transport_info; |
|
|
|
shmem_clear_channel(smbox->shmem); |
|
} |
|
|
|
static bool |
|
mailbox_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer) |
|
{ |
|
struct scmi_mailbox *smbox = cinfo->transport_info; |
|
|
|
return shmem_poll_done(smbox->shmem, xfer); |
|
} |
|
|
|
static const struct scmi_transport_ops scmi_mailbox_ops = { |
|
.chan_available = mailbox_chan_available, |
|
.chan_setup = mailbox_chan_setup, |
|
.chan_free = mailbox_chan_free, |
|
.send_message = mailbox_send_message, |
|
.mark_txdone = mailbox_mark_txdone, |
|
.fetch_response = mailbox_fetch_response, |
|
.fetch_notification = mailbox_fetch_notification, |
|
.clear_channel = mailbox_clear_channel, |
|
.poll_done = mailbox_poll_done, |
|
}; |
|
|
|
const struct scmi_desc scmi_mailbox_desc = { |
|
.ops = &scmi_mailbox_ops, |
|
.max_rx_timeout_ms = 30, /* We may increase this if required */ |
|
.max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */ |
|
.max_msg_size = 128, |
|
};
|
|
|